Lens barrel and imaging device

ABSTRACT

An interchangeable lens unit comprises a lens housing, a cam frame, and a zoom drive unit. The zoom drive unit is mounted to the lens housing, and rotationally drives the cam frame with respect to the lens housing. The lens housing has a substantially cylindrical main body component and a gear component that is disposed on the inner peripheral face of the main body component and to which the drive force of the zoom drive unit is transmitted. The gear component is disposed substantially in the middle of the main body component in the optical axis direction.

BACKGROUND

1. Technical Field

The technology disclosed herein relates to a lens barrel used in animaging device.

2. Background Information

Imaging devices that produce image data about a subject have beenrapidly growing in popularity in recent years. A lens barrel foradjusting the focal distance is installed in an imaging device. Knownimaging devices include, for example, integrated types of cameras andthose with an interchangeable lens. Integrated cameras have the lensbarrel built in. An interchangeable lens camera has a camera body and aninterchangeable lens unit that is mountable to and removable from thecamera body. For example, the lens barrel in this case is built into theinterchangeable lens unit.

SUMMARY

An actuator is built into this type of lens barrel. Examples ofactuators include a zoom motor used to adjust the focal distance, and afocus motor used to focus on the desired main subject.

These actuators transmit torque through a gear or other such member to asupport frame installed in the lens barrel. This allows the supportframe to be rotated, and this rotation may be used to move another framein the optical axis direction or to rotate it.

However, the actuator is usually disposed near the end of the supportframe, so if a gear is formed at the base of the support frame, theactuator and the gear will tend to interfere with each other. Therefore,with a lens barrel having a structure such as this, the layout of themembers ends up being less efficient and the product more bulky becauseof the need to avoid interference between the actuator and the gear.

One object of the technology disclosed herein is to provide a lensbarrel and an imaging device that is more compact.

The lens barrel disclosed herein comprises a first frame, a secondframe, a moving frame, and a drive actuator. The second frame isrotatably supported by the first frame. The moving frame is guided inthe optical axis direction by the second frame. The drive actuator ismounted on the first frame and rotationally drives the second frame withrespect to the first frame. The second frame has a substantiallycylindrical main body component and a gear component that is disposed onthe inner peripheral face of the main body component and to which thedrive force of the drive actuator is transmitted. The gear component isdisposed substantially in the middle of the main body component in theoptical axis direction.

With this lens barrel, since the gear component is disposedsubstantially in the middle of the main body component in the opticalaxis direction, a space is formed between the gear component and thefirst frame in the optical axis direction. This space can be utilizedmore effectively than when the gear component is formed at the end ofthe second frame on the first frame side. For example, other members canbe disposed in this space, so these members can be disposed moreefficiently.

Furthermore, compared to when the gear component is formed on the end ofthe second frame on the opposite side from the first frame, members ofthe drive actuator that mesh with the gear component is capable of beingsmaller in the optical axis direction, and this affords a more compactlens barrel.

A similar reduction in size may be achieved with an imaging devicecomprising this lens barrel.

BRIEF DESCRIPTION OF DRAWINGS

Referring now to the attached drawings which form a part of thisoriginal disclosure:

FIG. 1 is a diagram of the simplified configuration of a digital camera1;

FIG. 2 is a block diagram of a camera body 3;

FIG. 3A is a top view of the camera body 3, and FIG. 3B is a rear viewof the camera body 3;

FIG. 4 is an oblique perspective view of an interchangeable lens unit 2;

FIG. 5 is an exploded perspective view of the interchangeable lens unit2;

FIG. 6A is a simplified cross section of the interchangeable lens unit 2in its stowed state, FIG. 6B is a simplified cross section of theinterchangeable lens unit 2 at the wide angle end, and FIG. 6C is asimplified cross section of the interchangeable lens unit 2 at thetelephoto end;

FIG. 7A is a simplified cross section of the interchangeable lens unit 2in its stowed state, FIG. 7B is a simplified cross section of theinterchangeable lens unit 2 at the wide angle end, and FIG. 7C is asimplified cross section of the interchangeable lens unit 2 at thetelephoto end;

FIG. 8A is a inner peripheral development view of a fixed frame 50, andFIG. 8B is an inner peripheral development view of a cam frame 80;

FIG. 9A is a cross section along the IX-IX line in FIG. 8B, and FIG. 9Bis a cross section along the X-X line in FIG. 8B;

FIG. 10A is an oblique perspective view of the interchangeable lens unit2, and FIG. 10B is an oblique perspective view of the interchangeablelens unit 2 when a first lens support frame 51 has been removed;

FIG. 11A is an oblique perspective view of the interchangeable lens unit2 when a front lens frame 52 and a first support cover 57 have beenremoved from the state in FIG. 10A, and FIG. 11B is an obliqueperspective view of the interchangeable lens unit 2, which is similar toFIG. 11A except that an aperture unit 62 and the fixed frame 50 havebeen removed from the state in FIG. 11A;

FIG. 12A is an oblique perspective view of the interchangeable lens unit2, which is similar to FIG. 11B except that the cam frame 80 and amoving frame 53 have been removed from the state in FIG. 11B, and FIG.12B is an oblique perspective view of the interchangeable lens unit 2,which is similar to FIG. 12A except that a correction lens frame 54 anda second support cover 65 have been removed from the state in FIG. 12A;

FIG. 13 is an oblique perspective view of a fourth lens support frame, afocus motor 64, and a third lens support frame 55;

FIG. 14 shows the layout of a zoom driveshaft 87 a and a secondtransmission gear 86;

FIG. 15 shows the layout of the cam frame 80 and a zoom motor 87;

FIG. 16A is a plan view (rear face side) of a second lens support frame69, FIG. 16B is a plan view (front face side) of the second lens supportframe 69, and FIG. 16C is a simplified cross section of the second lenssupport frame 69;

FIG. 17A is a simplified cross section of the interchangeable lens unit2 in its stowed state, and FIG. 17B is a simplified cross section of theinterchangeable lens unit 2 at the telephoto end;

FIG. 18A is an oblique perspective view of a base member 93, FIG. 18B isan oblique perspective view of a fourth lens support frame 56, alens-side contact unit 91, and an electrical board 92, FIG. 18C is anoblique perspective view of the fourth lens support frame 56 and theelectrical board 92, and FIG. 18D is an oblique perspective view of thefourth lens support frame 56;

FIG. 19 is a plan view of a control lever unit 88;

FIG. 20 shows the positional relations of the various members in planview when viewed in the optical axis direction;

FIG. 21 is a simplified cross section of an interchangeable lens unit302 in its stowed state; and

FIG. 22A is a simplified layout diagram of a piezoelectric actuator 187,FIG. 22B is a diagram illustrating the operation of the piezoelectricactuator 187, and FIG. 22C is a simplified layout diagram of thepiezoelectric actuator 187.

DESCRIPTION OF EMBODIMENTS

Selected embodiments will now be explained with reference to thedrawings. It will be apparent to those skilled in the art from thisdisclosure that the following descriptions of the embodiments areprovided for illustration only and not for the purpose of limiting theinvention as defined by the appended claims and their equivalents.

First Embodiment

Overview of Digital Camera

A digital camera 1 will be described through reference to FIGS. 1 to 3Aand 3B. As shown in FIG. 1, the digital camera 1 (an example of animaging device) is an interchangeable lens type of digital camera, andmainly comprises a camera body 3 (an example of a camera body) and aninterchangeable lens unit 2 (an example of a lens barrel) that isremovably mounted to the camera body 3. The interchangeable lens unit 2is removably mounted to a body mount 4 provided to the front face of thecamera body 3, via a lens mount 95.

This digital camera 1 is what is known as a mirror-less single-lenscamera, in which no quick-return mirror is installed between the bodymount 4 and an imaging sensor 11.

Simplified Configuration of Interchangeable Lens Unit

The simplified configuration of the interchangeable lens unit 2 will bedescribed through reference to FIG. 1 and FIGS. 4 to 7. As shown in FIG.1, the interchangeable lens unit 2 has an optical system O, a lenssupport mechanism 71 that supports the optical system O, a focusadjusting unit 72, an aperture adjustment unit 73, a blur correctionunit 74, and a lens controller 40. Each of these will be describedbelow.

(1) Optical System

The optical system O is a lens system for forming an optical image of asubject. More specifically, as shown in FIGS. 6 and 7, the opticalsystem O has a first lens group G1, a second lens group G2, a third lensgroup G3, and a fourth lens group G4. The optical system O has anoptical axis AX defined by these lens groups. A direction parallel tothe optical axis AX will hereinafter be called the optical axisdirection.

The first lens group G1 is disposed the farthest out on the subject sideof all these lens groups, and has a first lens L1, a second lens L2, anda third lens L3. The second lens group G2 has a fourth lens L4, a fifthlens L5, a sixth lens L6, and a seventh lens L7. The seventh lens L7 isa correcting lens that corrects image blur caused by movement of thedigital camera 1, and is disposed movably in a plane that isperpendicular to the optical axis direction. The third lens group G3 hasan eighth lens L8 that functions as a focusing lens. The eighth lens L8is disposed movably in the optical axis direction. The fourth lens groupG4 is disposed farthest out on the image plane side of all these lensgroups, and has a ninth lens L9 (an example of a rear lens element).

(2) Lens Support Mechanism

The lens support mechanism 71 is used to support the first to fourthlens groups G1 to G4. As shown in FIG. 5, the lens support mechanism 71has a lens housing 2 a, a cam frame 80, a first lens support frame 51, asecond lens support frame 69, a third lens support frame 55, a lens-sidecontact unit 91, an electrical board 92, a control lever unit 88, and anaperture unit 62.

(2-1) Lens Housing 2 a

The lens housing 2 a (an example of a first frame) constitutes part ofthe outer case of the interchangeable lens unit 2, and has a base member93 (an example of a base member) and a fixed frame 50 (an example of anouter frame).

The base member 93 has a lens mount 95, a light blocking frame 96, and afourth lens support frame 56. The base member 93 is fixed to the end ofthe fixed frame 50.

The lens mount 95 (an example of a lens mount) is an annular member thatis mounted to the body mount 4 of the camera body 3, and has a bayonet95 a (see FIG. 18A) that is linkable to the body mount 4. The lightblocking frame 96, which blocks out unwanted light, is attached to thelens mount 95. The fourth lens support frame 56 is also fixed to thelens mount 95.

The fourth lens group G4 is fixed to the fourth lens support frame 56.That is, the fourth lens group G4 is a lens group that does not move inthe optical axis direction. The fourth lens support frame 56 has asupport frame main body 56 b and two rectilinear guide plates 56 a thatextend in the optical axis direction from the support frame main body 56b. The rectilinear guide plates 56 a are inserted into rectilinear guidegrooves 53 k (discussed below) of a moving frame 53, respectively, andrestrict the rotation of the second lens support frame 69. Therectilinear guide plates 56 a are disposed on the inner peripheral sideof the cam frame 80.

As discussed below, a zoom motor 87, a transmission mechanism 84 and afocus motor 64 are mounted to the base member 93. In this embodiment,the zoom motor 87, the transmission mechanism 84, and the focus motor 64are fixed to the fourth lens support frame 56.

The fixed frame 50 is fixed by three screws 50 f to the outer peripheralpart of the lens mount 95. The fixed frame 50 is a substantiallycylindrical member that rotatably supports the cam frame 80. As shown inFIG. 8A, the fixed frame 50 has a plurality of rectilinear grooves 50 aformed on its inner peripheral face. The rectilinear grooves 50 a extendin the optical axis direction, and guide rectilinear protrusions 51 b(discussed below) of the first lens support frame 51 in the optical axisdirection. Since the rectilinear protrusions 51 b are guided in theoptical axis direction by the rectilinear grooves 50 a, the first lenssupport frame 51 is able to move in the optical axis direction withoutrotating with respect to the fixed frame 50.

As shown in FIG. 8A, the fixed frame 50 has three guide cam grooves 50 bformed on its inner peripheral face. The guide cam grooves 50 b areprovided in order to guide the cam frame 80 in the optical axisdirection. Guide cam followers 83 (discussed below) of the cam frame 80are inserted into the guide cam grooves 50 b.

Also, the fixed frame 50 is fixed to the lens mount 95 of the basemember 93 by three screws 50 f. Here, the portions where the fixed frame50 is fixed to the base member 93 by the screws 50 f will be called thefixed components 50 e. The three fixed components 50 e are disposedequidistantly spaced in the peripheral direction. Also, the three fixedcomponents 50 e are disposed between the three guide cam grooves 50 b inthe peripheral direction, respectively, and do not interfere with theguide cam grooves 50 b. It could also be said that the three guide camgrooves 50 b are disposed between the three fixed components 50 e in theperipheral direction, respectively.

A concave portion 50 c is formed on the outer peripheral face of thefixed frame 50. The control lever unit 88 (discussed below) is fittedinto this concave portion 50 c. The concave portion 50 c is disposedmore on the subject side (the opposite side from the image plane) thanthe guide cam grooves 50 b.

(2-2) Lens-Side Contact Unit 91

The lens-side contact unit 91 (an example of an electrical contact) isfixed to the lens housing 2 a, and configured to be electricallyconnected to the camera body 3 (an example of an external device) viathe body mount 4. As shown in FIGS. 18A and 18B, in this embodiment thelens-side contact unit 91 is fixed to the lens mount 95. The lens-sidecontact unit 91 extends in an arc shape around the optical axis AX. Thelens-side contact unit 91 has a plurality of contacts disposed in an arcshape. The lens-side contact unit 91 is electrically connected to theelectrical board 92.

(2-3) Electrical Board 92

The electrical board 92 (an example of an electrical board) is fixed tothe lens housing 2 a, and is electrically connected to the lens-sidecontact unit 91. In this embodiment, as shown in FIGS. 18B and 18C, theelectrical board 92 is fixed to the fourth lens support frame 56. Thelens controller 40, a focus drive control component 41, and a correctioncontroller 48 are mounted as electronic parts to the electrical board92. As shown in FIGS. 6 and 12, the electrical board 92 is disposed onthe inner peripheral side of the cam frame 80 when viewed in the opticalaxis direction. In the stowed state as shown in FIG. 6A, the cam frame80 is allowed to be close to base member 93 at a location that overlapthe electrical board 92 when viewed in the direction perpendicular tothe optical axis direction. This allows the cam frame 80 to be closer tothe base member 93, and makes it possible to reduce the size of theinterchangeable lens unit 2.

(2-4) Cam Frame 80

The cam frame 80 is rotatably supported by the lens housing 2 a. Moreprecisely, the cam frame 80 is supported rotatably around the opticalaxis AX by the fixed frame 50, and moves in the optical axis directionwhile rotating around the inner peripheral side of the fixed frame 50respectively, or rotates without moving in the optical axis direction onthe inner peripheral side of the fixed frame 50. The cam frame 80 isrotationally driven by a zoom drive unit 45.

The cam frame 80 has a substantially cylindrical main body component 81,the three guide cam followers 83, and a gear component 82. The threeguide cam followers 83 are inserted into the three guide cam grooves 50b of the fixed frame 50, and protrude outward from the outer peripheralface of the main body component 81. When the cam frame 80 rotates withrespect to the fixed frame 50, the guide cam followers 83 are guided bythe guide cam grooves 50 b. As a result, the cam frame 80 moves in theoptical axis direction while rotating with respect to the fixed frame50, or rotates with respect to the fixed frame 50 without moving in theoptical axis direction. In this embodiment, when not in use (stowedstate), the cam frame 80 moves more to the image plane side than theregion of movement in the optical axis direction with respect to thelens housing 2 a when in use. That is, when in use (see FIG. 6B), thecam frame 80 is deployed to the subject side with respect to the fixedframe 50, but when not in use (see FIG. 6A), the cam frame 80 moves tothe image plane side with respect to the fixed frame 50, and is stowedinside the fixed frame 50.

The gear component 82 is disposed on the inner peripheral face of themain body component 81, and protrudes inward from the inner peripheralface of the main body component 81. The gear component 82 meshes with afirst transmission gear 85 (discussed below) of the zoom drive unit 45.Drive force from the zoom drive unit 45 (more precisely, thetransmission mechanism 84) is transmitted to the gear component 82.

The gear component 82 is disposed substantially in the middle of themain body component 81 in the optical axis direction. In a state inwhich the cam frame 80 has moved closest to the base member 93, aholding space S (an example of a holding space) is left between the gearcomponent 82 and the base member 93 in the optical axis direction (seeFIGS. 6A and 7A, for example).

The zoom drive unit 45 (the zoom motor 87 and the transmission mechanism84) is disposed on the inner peripheral side of the main body 81. Thezoom motor 87 and/or the transmission mechanism 84 is disposed more tothe image plane side than the gear component 82. In a state in which thecam frame 80 is closest to the base member 93, the zoom motor 87 and thetransmission mechanism 84 are inside the holding space S (see FIG. 6A,for example).

The two ends of the gear component 82 are at different positions in theoptical axis direction. More specifically, as shown in FIG. 8A, the gearcomponent 82 has a first gear component 82 a and a second gear component82 b. The first gear component 82 a extends in the peripheral directionaround the inner peripheral face of the main body 81, and is used whenthe cam frame 80 rotates without moving in the optical axis directionwith respect to the fixed frame 50. Meanwhile, the second gear component82 b is inclined with respect to the peripheral direction, and isdisposed so as to gradually approach the base member 93 from the firstgear component 82 a. The second gear component 82 b is used when the camframe 80 moves in the optical axis direction while rotating with respectto the fixed frame 50.

As shown in FIG. 8A, the cam frame 80 has three inner peripheral camgrooves 83 a (an example of a first cam groove, second cam groove, andthird cam groove) and three outer peripheral cam grooves 83 b (anexample of outer peripheral cam grooves).

The inner peripheral cam grooves 83 a are provided to guide the secondlens support frame 69 in the optical axis direction, and are disposed onthe inner peripheral face of the main body 81. Three cam followers 53 e,53 f, and 53 g of the moving frame 53 are inserted into the three guidecam followers 83, respectively. The gear component 82 is disposed so asto avoid the inner peripheral cam grooves 83 a. The second gearcomponent 82 b of the gear component 82 is close to the inclined portionof the inner peripheral cam grooves 83 a, and is disposed substantiallyalong this inclined portion. Part of the inner peripheral cam grooves 83a (an example of first cam grooves) is disposed on the image plane side(base member 93 side) of the gear component 82 (more precisely, thefirst gear component 82 a).

The outer peripheral cam grooves 83 b are provided to guide the firstlens support frame 51 in the optical axis direction, and are disposed onthe outer peripheral face of the main body 81. Three inner peripheralcam followers 51 d (discussed below) of the first lens support frame 51are inserted into the three outer peripheral cam grooves 83 b,respectively.

The dimensions of the gear component 82 in the radial direction will nowbe described. As shown in FIG. 9A, the gear component 82 protrudesinward in the radial direction from the inner peripheral face of themain body 81. Accordingly, the inside radius R1 of the bottom face ofthe inner peripheral cam grooves 83 a is greater than the root radius R2of the gear component 82. Also, the root radius R2 of the gear component82 is less than the inside radius R3 of the main body 81. Therefore,even if the gear component 82 and the inner peripheral cam grooves 83 aoverlap, for example, this prevents the function of the inner peripheralcam grooves 83 a from being lost at the overlapping portions. Also, evenif the outer peripheral cam grooves 83 b pass through the outerperipheral side of the gear component 82, a decrease in the strength ofthe cam frame 80 is suppressible. As shown in FIG. 9B, the root radiusR2 is less than the inside radii R4 of the bottom faces of the outerperipheral cam grooves 83 b.

(2-5) Zoom Drive Unit 45

The zoom drive unit 45 (an example of a drive actuator) is provided toadjust the focal distance of the optical system O. The zoom drive unit45 is mounted to the lens housing 2 a (more precisely, the fourth lenssupport frame 56), and rotationally drives the cam frame 80 with respectto the lens housing 2 a. The zoom drive unit 45 has the zoom motor 87and the transmission mechanism 84.

The zoom motor 87 (an example of a first actuator) is a DC motor, forexample, and has a zoom driveshaft 87 a (an example of a driveshaft)that outputs drive force. The zoom motor 87 may instead be another kindof motor, such as a stepping motor.

The zoom motor 87 is mounted to the lens housing 2 a (more precisely,the fourth lens support frame 56). The lengthwise direction L of thezoom motor 87 is different from the optical axis direction. The“lengthwise direction L of the zoom motor 87” means a direction parallelto the longest side of an imaginary cuboid when the zoom motor 87 iselevated as a cuboid. Since the zoom motor 87 has the slender zoomdriveshaft 87 a, the lengthwise direction L of the zoom motor 87 isparallel to the rotational axis E1 of the zoom driveshaft 87 a. Sincethe lengthwise direction L of the zoom motor 87 is parallel to therotational axis E1, the rotational axis E1 of the zoom driveshaft 87 ain a different direction from the optical axis direction, just as thelengthwise direction L is. In this embodiment, as shown in FIG. 12B, thelengthwise direction L and the rotational axis E1 of the zoom driveshaft87 a are disposed substantially parallel to a plane that isperpendicular to the optical axis direction.

The transmission mechanism 84 (an example of a transmission mechanism)transmits drive force from the zoom driveshaft 87 a to the cam frame 80.The transmission mechanism 84 is mounted to the fourth lens supportframe 56.

The transmission mechanism 84 reduces the rotational speed of the zoomdriveshaft 87 a and transmits this rotation to the gear component 82 ofthe cam frame 80. More specifically, as shown in FIG. 12B, thetransmission mechanism 84 has a first transmission gear 85 (an exampleof a first transmission gear member, and an example of a drive gearmember) that meshes with the gear component 82, and a secondtransmission gear 86 (an example of a second transmission gear member)that meshes with the first transmission gear 85 and transmits driveforce from the zoom driveshaft 87 a to the first transmission gear 85.

The first transmission gear 85 is rotatably supported by the fourth lenssupport frame 56 and a first support cover 57. The rotational axis E2 ofthe first transmission gear 85 is parallel to the optical axisdirection, but the rotational axis E3 of the second transmission gear 86faces in a different direction from the optical axis direction. In thisembodiment, the rotational axis E3 of the second transmission gear 86 isinclined with respect to a plane that is perpendicular to the opticalaxis direction.

The zoom driveshaft 87 a has an output gear 87 b (an example of anoutput gear) that outputs drive force. The second transmission gear 86has a first intermediate gear 86 a that meshes with the output gear 87b, and a second intermediate gear 86 b including a worm gear that mesheswith the first transmission gear 85. The first intermediate gear 86 a isa spur gear, for example. As shown in FIG. 12A, a second support cover65 is fixed to the fourth lens support frame 56. The second transmissiongear 86 is covered by the second support cover 65. The secondtransmission gear 86 is rotatably supported by the fourth lens supportframe 56 and the second support cover 65.

As shown in FIG. 14, the rotational axis E3 of the second transmissiongear 86 is inclined by substantially the same angle θ4 as the lead angleof the second intermediate gear 86 b, with respect to a plane that isperpendicular to the optical axis direction. FIG. 14 shows thepositional relation between the output gear 87 b and the secondtransmission gear 86 when viewed in a direction parallel to therotational axis E1 of the zoom driveshaft 87 a. The output gear 87 b isdisposed between the second transmission gear 86 and the firstintermediate gear 86 a. The second intermediate gear 86 b is disposedcloser to the base member 93 than the first intermediate gear 86 a.

As shown in FIG. 15, the rotational axis E1 of the zoom driveshaft 87 ais disposed substantially along the peripheral direction of the camframe 80. Here, the phrase “the rotational axis E1 of the zoomdriveshaft 87 a is disposed substantially along the peripheral directionof the cam frame 80” means that, for example, in FIG. 15, the distancesR11 and R12 from the points F1 and F2 where the ends of the zoom motor87 intersect with the rotational axis E1 to the optical axis AX aresubstantially the same. This allows the zoom motor 87 to be efficientlydisposed along the inner peripheral face of the cam frame 80.

(2-6) First Lens Support Frame 51

The first lens group G1 is fixed to the first lens support frame 51. Thefirst lens support frame 51 is supported movably in the optical axisdirection by the fixed frame 50 of the lens housing 2 a, and itsrotation is restricted by the fixed frame 50. When the cam frame 80rotates with respect to the fixed frame 50, the first lens support frame51 is driven in the optical axis direction by the cam frame 80.

As shown in FIG. 5 and FIGS. 6A to 7C, the first lens support frame 51has three rectilinear protrusions 51 b and three inner peripheral camfollowers 51 d. The three rectilinear protrusions 51 b are inserted intothe three rectilinear grooves 50 a, respectively.

The three inner peripheral cam followers 51 d are inserted into theouter peripheral cam grooves 83 b, respectively. Since the rectilinearprotrusions 51 b are guided in the optical axis direction by therectilinear grooves 50 a, the first lens support frame 51 is able tomove in the optical axis direction without rotating with respect to thefixed frame 50. Also, when the cam frame 80 rotates with respect to thefixed frame 50, the inner peripheral cam followers 51 d are guided bythe outer peripheral cam grooves 83 b, so the first lens support frame51 moves in the optical axis direction with respect to the fixed frame50 according to the shape of the outer peripheral cam grooves 83 b.

Also, a threaded portion 51 e is formed on the front face of the firstlens support frame 51. An optical filter, such as a polarizing filter ora protective filter, or a conversion lens can be attached to thethreaded portion 51 e.

(2-7) Second Lens Support Frame 69

The second lens support frame 69 supports the second lens group G2 andis guided by the cam frame 80 in the optical axis direction with respectto the lens housing 2 a. More specifically, as shown in FIG. 5, thesecond lens support frame 69 has a front lens frame 52, the apertureunit 62, the moving frame 53, a correction lens frame 54, and acorrection drive unit 46. The front lens frame 52, the aperture unit 62,the moving frame 53, the correction lens frame 54, and the correctiondrive unit 46 to be capable of moving as one in the optical axisdirection.

The fourth lens L4 is fixed to the front lens frame 52. The front lensframe 52 is fixed to the moving frame 53 by screws, for example. Thefifth lens L5 and the sixth lens L6 are fixed to the moving frame 53 byadhesive, for example. When the fifth lens L5 and the sixth lens L6 arefixed to the moving frame 53, the positions of the fifth lens L5 and thesixth lens L6 with respect to the fourth lens L4 are adjusted so thatthe optical axis center of the fifth lens L5 and the sixth lens L6 andthe optical axis center of the fourth lens L4 will be disposedcoaxially. After position adjustment, three adhesive reservoirs 53 i(see FIGS. 16A and 16C) provided to the moving frame 53 are coated withan adhesive agent and the adhesive is cured, which fixes the fifth lensL5 and the sixth lens L6 to the moving frame 53. How the front lensframe 52 is fixed is not limited to the above method, and adhesivebonding or other fixing methods may also be used. Also, how the fifthlens L5 and the sixth lens L6 are fixed is not limited to the abovemethod, and some other fixing method may be used instead.

The aperture unit 62 is disposed movably in the optical axis directionwith respect to the lens housing 2 a, and adjusts the amount of light.The aperture unit 62 has a plurality of aperture vanes 62 c that isconfigured to vary the optical path diameter, an aperture support frame62 b that supports the aperture vanes 62 c, and an aperture drive motor62 a that adjusts the amount of light by driving the plurality ofaperture vanes 62 c. The aperture drive motor 62 a is fixed to theaperture support frame 62 b, and protrudes on the subject side from theaperture support frame 62 b. The aperture unit 62 is disposed betweenthe moving frame 53 and the front lens frame 52.

The fifth lens L5 and the sixth lens L6 are fixed to the moving frame53. The moving frame 53 is guided by the cam frame 80 in the opticalaxis direction with respect to the lens housing 2 a. More specifically,as shown in FIGS. 16A to 16C, the moving frame 53 has a moving framemain body 53 a, the three cam followers 53 e, 53 f, and 53 g, a holderportion 53 c, and the two rectilinear guide grooves 53 k. The movingframe main body 53 a is a substantially annular member, but one part iscut away on the outer peripheral side. The three cam followers 53 e, 53f, and 53 g protrude outward from the outer peripheral part of themoving frame main body 53 a, and are inserted into the three innerperipheral cam grooves 83 a of the cam frame 80, respectively.

The two rectilinear guide grooves 53 k extend in the optical axisdirection, and are disposed spaced apart in the peripheral direction.The rectilinear guide plates 56 a of the fourth lens support frame 56are inserted into the rectilinear guide grooves 53 k, respectively. Thisallows the moving frame 53 to move in the optical axis direction withoutrotating with respect to the lens housing 2 a.

The holder portion 53 c is a cylinder that is closed at one end, andprotrudes on the subject side from the moving frame main body 53 a. Theend 59 a of a focusing sub-shaft 59 is configured to be inserted in theoptical axis direction into the holder portion 53 c. When the movingframe main body 53 a approaches the third lens support frame 55, the endof the focusing sub-shaft 59 is inserted into the holder portion 53 c.This prevents the moving frame 53 from interfering with the focusingsub-shaft 59, and ensures a large range of motion for both the thirdlens support frame 55 and the moving frame 53.

As shown in FIG. 16A, the correction lens frame 54 is disposed on theimage plane side of the moving frame 53, and is supported movably in aplane that is perpendicular to the optical axis direction by the movingframe 53. The seventh lens L7 is fixed to the correction lens frame 54.

A rotational support shaft 49 a, a first slide pole 43 a, and a secondslide pole 43 b are fixed to the moving frame 53. The correction lensframe 54 is supported movably in the pitch direction with respect to themoving frame 53 by the first slide pole 43 a and the second slide pole43 b. Also, movement of the correction lens frame 54 in the optical axisdirection with respect to the moving frame 53 is restricted by the firstslide pole 43 a and the second slide pole 43 b. Further, the correctionlens frame 54 is guided movably in the yaw direction by the rotationalsupport shaft 49 a, and rotates around the rotational support shaft 49a. This allows the seventh lens L7 to be moved in a plane that isperpendicular to the optical axis AX.

As shown in FIG. 16A, a restricting shaft 49 b is fixed to the movingframe 53. The correction lens frame 54 has a restricted part 54 c havinga hole 54 d. The restricting shaft 49 b is inserted into the hole 54 dof the restricted part 54 c and restricts the movement of the correctionlens frame 54 with respect to the moving frame 53 to a specific range.

The method for assembling the correction lens frame 54 will now bedescribed. First, the rotational support shaft 49 a, the first slidepole 43 a, and the second slide pole 43 b are fixed to the moving frame53. Three support grooves (not shown) are formed in the correction lensframe 54. The correction lens frame 54 is attached to the moving frame53 so that the first slide pole 43 a will fit into two of the supportgrooves, and the second slide pole 43 b will fit into the remainingsupport groove. At this point, the rotational support shaft 49 a isfitted into a rotational support groove (not shown) of the correctionlens frame 54. As a result, the correction lens frame 54 is supported bythe moving frame 53 movably in a plane that is perpendicular to theoptical axis direction. At this point movement of the correction lensframe 54 in the optical axis direction is restricted with respect to themoving frame 53.

Next, the restricting shaft 49 b is fixed by press-fitting, for example,to the moving frame 53. The restricting shaft 49 b is press-fitted intothe hole 54 d in the restricted part 54 c of the correction lens frame54, and is disposed at a position that does not overlap the apertureunit 62 when viewed in the optical axis direction. Therefore, when therestricting shaft 49 b is press-fitted to the moving frame 53, the faceof the moving frame 53 on the opposite side from the restricting shaft49 b (the subject side) is directly received by a jig, allowing the workof press-fitting the restricting shaft 49 b to be carried out easily.

The correction lens frame 54 is attached to the moving frame 53 in thismanner.

The correction lens frame 54 is driven in two directions in a plane thatis perpendicular to the optical axis direction, by the correction driveunit 46. The correction drive unit 46 has a first magnet 54 a, a secondmagnet 54 b, a first yoke 44 a, a second yoke 44 b, a first coil 46 a,and a second coil 46 b. As shown in FIG. 12A, the first magnet 54 a andthe second magnet 54 b are fixed on the subject side of the correctionlens frame 54. The first yoke 44 a is attached to the face of the firstmagnet 54 a on the opposite side from the first coil 46 a (the subjectside). The second yoke 44 b is attached to the face of the second magnet54 b on the opposite side from the second coil 46 b (the subject side).Meanwhile, the first coil 46 a and the second coil 46 b are fixed on theimage plane side of the moving frame 53. The first magnet 54 a, thefirst yoke 44 a and the first coil 46 a constitute an electromagneticactuator. The second magnet 54 b, the second yoke 44 b and the secondcoil 46 b constitute an electromagnetic actuator. The electromagneticforce of these electromagnetic actuators drives the correction lensframe 54 in a plane that is perpendicular to the optical axis AX.

The configuration of the moving frame 53 will now be described infurther detail.

As shown in FIGS. 16A to 16C, when the second lens support frame 69 isclosest to the base member 93, the zoom motor 87 is housed inside themoving frame 53 as shown in FIG. 16C, for example. At this point, thecam follower 53 e (an example of a first cam follower) is disposed onthe outer peripheral side of the zoom motor 87 when viewed in theoptical axis direction.

The focus motor 64, the first transmission gear 85, and a focusing mainshaft 58 are disposed in the peripheral direction between the camfollower 53 e and the cam follower 53 f. A cut-out 53 d is formed in theperipheral direction between the two cam followers 53 e and 53 f. Thefocus motor 64 is disposed in the peripheral direction between the camfollower 53 e and the cam follower 53 f when viewed in the optical axisdirection. The focus motor 64, the first transmission gear 85, and thefocusing main shaft 58 are disposed within the cut-out 53 d.

Because the focus motor 64, the first transmission gear 85, and thefocusing main shaft 58 are disposed within the cut-out 53 d, arelatively large spacing is ensured in the peripheral direction betweenthe cam follower 53 e and the cam follower 53 f. More specifically, asshown in FIGS. 16A and 16B, the central angle θ1 between the camfollower 53 e and the cam follower 53 f is greater than the centralangle θ2 between the cam follower 53 f and the cam follower 53 g, and isgreater than the central angle θ3 between the cam follower 53 g and thecam follower 53 e. That is, the central angle θ1 is greater than 120degrees. The central angle θ1 may be set to 120 degrees or more. In thisembodiment, the central angle θ2 is the same as the central angle θ3.

Also, since the cut-out 53 d is formed relatively large in theperipheral direction, the gear component 82 is capable of moving intothe cut-out 53 d. More specifically, as shown in FIGS. 7A to 7C, thegear component 82 of the cam frame 80 moves into the cut-out 53 d in thecourse of the moving frame 53 being guided in the optical axis directionby the cam frame 80. Because the cut-out 53 d is provided, the gearcomponent 82 does not hinder the movement of the second lens supportframe 69, so the interchangeable lens unit 2 is made thinner.

As shown in FIG. 6A, in the stowed state of the interchangeable lensunit 2, part of the outer peripheral part of the moving frame 53 goesinto the stowage space S formed between the gear component 82 and thebase member 93. Consequently, the stowage space S on the image planeside of the gear component 82 is more effectively utilized, theinterchangeable lens unit 2 is made even more compact.

(2-8) Third Lens Support Frame 55

The third lens group G3 (eighth lens L8) is fixed to the third lenssupport frame 55. The third lens support frame 55 is disposed movably inthe optical axis direction with respect to the lens housing 2 a. Thethird lens support frame 55 is supported movably in the optical axisdirection by the lens housing 2 a. More specifically, the third lenssupport frame 55 has a bearing component 55 a, a rotation restrictingarm 55 b, and a rack 55 c.

The bearing component 55 a extends in the optical axis direction and hasa sliding hole. The focusing main shaft 58 is inserted into this slidinghole. A first end 58 a of the focusing main shaft 58 is fixed to thefourth lens support frame 56. A second end 58 b of the focusing mainshaft 58 is fixed to the first support cover 57, which is fixed to thefourth lens support frame 56. Therefore, the third lens support frame 55is guided in the optical axis direction by the focusing main shaft 58.

The focusing sub-shaft 59 is fixed to the fourth lens support frame 56.The focusing sub-shaft 59 is inserted into a restricting hole 55 d inthe rotation restricting arm 55 b of the third lens support frame 55.The focusing sub-shaft 59 restricts rotation of the third lens supportframe 55 around the focusing main shaft 58 with respect to the lenshousing 2 a.

The rack 55 c meshes with a lead screw of a focus driveshaft 64 a of thefocus motor 64. When the focus driveshaft 64 a rotates, the rack 55 c isguided in the optical axis direction by the lead screw, and the thirdlens support frame 55 moves in the optical axis direction with respectto the fourth lens support frame 56.

(2-9) Focus Motor 64

The focus motor 64 has the focus driveshaft 64 a (an example of arotating shaft) that outputs drive force, and drives the third lenssupport frame 55 in the optical axis direction. The rotational axis E4of the focus driveshaft 64 a is substantially parallel to the opticalaxis direction. The focus driveshaft 64 a has a lead screw that mesheswith the rack 55 c of the third lens support frame 55. When the focusdriveshaft 64 a rotates, the rack 55 c is driven in the optical axisdirection by the lead screw. This is how the third lens support frame 55is driven in the optical axis direction.

The first transmission gear 85 is rotatably supported by the firstsupport cover 57 and the fourth lens support frame 56. Also, the zoommotor 87, the focusing main shaft 58, the bearing component 55 a, andthe focus motor 64 are housed inside the first support cover 57. Thefirst support cover 57 has a shape that is complementary with thecut-out 53 d in the moving frame 53, and when the second lens supportframe 69 moves toward the base member 93, the first support cover 57enters the cut-out 53 d.

(2-10) Control lever Unit 88

The control lever unit 88 has a zoom lever 89, a support base 88 a, azoom lever detect component 90 (see FIG. 1), a focus lever 98, and afocus lever detect component 99.

The zoom lever 89 is provided to adjust the focal distance of theoptical system O, and is disposed on the outer peripheral part of thefixed frame 50. The zoom lever 89 is provided rotatably in theperipheral direction with respect to the lens housing 2 a. Morespecifically, the zoom lever 89 is supported movably in the peripheraldirection by the fixed frame 50 via the support base 88 a. The zoomlever 89 is able to move in two directions: toward the wide angle sideand toward the telephoto side.

The focus lever 98 is provided to adjust the imaging distance from thedigital camera 1 to the main subject in focus (also called the subjectdistance), and is disposed on the outer peripheral part of the fixedframe 50. The focus lever 98 is provided rotatably in the peripheraldirection with respect to the lens housing 2 a. More specifically, thefocus lever 98 is supported movably in the peripheral direction by thefixed frame 50 via the support base 88 a. The focus lever 98 is able tomove in two directions: toward the close-up side and toward the infinityside.

The support base 88 a movably supports the zoom lever 89 and the focuslever 98, and is fixed to the outer peripheral part of the fixed frame50. More precisely, the support base 88 a is fitted into the concaveportion 50 c of the fixed frame 50 (see FIG. 19). Part of the supportbase 88 a goes into the inside from the outer peripheral edge of thefixed frame 50. Accordingly, part of the zoom lever 89 and part of thefocus lever 98 also go into the inside from the outer peripheral edge ofthe fixed frame 50. Thus, the thickness of the fixed frame 50 iseffectively utilized as a space for installing the control lever unit 88and the focus lever 98.

The zoom lever detect component 90 is provided to detect the position ofthe zoom lever 89, and is electrically connected to the lens controller40. The lens controller 40 is configured to identify the direction inwhich the zoom lever 89 is operated on the basis of the detection resultof the zoom lever detect component 90.

The focus lever detect component 99 is provided to detect the positionof the focus lever 98, and is electrically connected to the lenscontroller 40. The lens controller 40 is configured to identify thedirection in which the focus lever 98 is operated on the basis of thedetection result of the focus lever detect component 99.

The layout of the control lever unit 88 will now be described in greaterdetail. As shown in FIG. 8A, the zoom lever 89 and the focus lever 98are disposed at positions that do not overlap the three guide camgrooves 50 b. More precisely, the zoom lever 89 and the focus lever 98are disposed at positions that are farther from the base member 93 inthe optical axis direction than the three guide cam grooves 50 b. Inother words, the zoom lever 89 and the focus lever 98 are disposed moretoward the subject side than the three guide cam grooves 50 b in theoptical axis direction.

(3) Aperture Adjustment Unit 73

As shown in FIG. 1, the aperture adjustment unit 73 has theabove-mentioned aperture unit 62 and an aperture drive control component42 that controls the aperture drive motor 62 a of the aperture unit 62.The aperture drive motor 62 a is a stepping motor, for example. Theaperture drive control component 42 sends drive pulses to the aperturedrive motor 62 a on the basis of a command from the lens controller 40.This allows the aperture value of the optical system O to be adjusted tothe desired value.

(4) Focus Adjusting Unit 72

As shown in FIG. 1, the focus adjusting unit 72 has the focus motor 64,the focus drive control component 41, and a photosensor 67. As discussedabove, the focus motor 64 is fixed to the fourth lens support frame 56,and drives the third lens support frame 55 in the optical axisdirection. In this embodiment, the focus motor 64 is a stepping motor.

The focus drive control component 41 sends drive pulses to the focusmotor 64 on the basis of a command from the lens controller 40. Thephotosensor 67 detects whether or not the third lens support frame 55 isdisposed at a specific position in the optical axis direction (the homeposition). The photosensor 67 is fixed to the fourth lens support frame56, for example. This photosensor 67 has a light emitting component (notshown) and a light receiving component (not shown). When the detectedpart (not shown) of the third lens support frame 55 moves in between thelight emitting component and the light receiving component, thephotosensor 67 detects the detected part. The lens controller 40 iscapable of detecting that the third lens support frame 55 is in the homeposition on the basis of the detection result of the photosensor 67.

The photosensor 67 is capable of detecting whether or not the third lenssupport frame 55 is in the home position, and detecting the presence ofa focus home point detected part 52 f. That is, the photosensor 67 iscapable of detecting the home position of the fourth lens support frame56, that is, a focus movable unit 94 with respect to the lens mount 95.The photosensor 67 may instead be some other kind of sensor, such as acombination of a magnet and a magnetic sensor.

(5) Blur Correction Unit

As shown in FIG. 1, the blur correction unit 74 is used to suppressblurring of the optical image with respect to the imaging sensor 11,which is attributable to movement of the digital camera 1, and has thecorrection drive unit 46, a first position detection sensor 47 a, asecond position detection sensor 47 b, and the correction controller 48.

As discussed above, the correction drive unit 46 drives the correctionlens frame 54 in a plane that is perpendicular to the optical axis AX.More specifically, as shown in FIG. 16A, the correction drive unit 46has the first magnet 54 a, the second magnet 54 b, the first coil 46 a,and the second coil 46 b. The first magnet 54 a and the second magnet 54b are fixed to the correction lens frame 54. The first coil 46 a and thesecond coil 46 b are fixed to the moving frame 53. The first magnet 54 aand the first coil 46 a constitute an electromagnetic actuator, anddrive the correction lens frame 54 in the pitch direction with respectto the moving frame 53 by electromagnetic force. The second magnet 54 band the second coil 46 b constitute an electromagnetic actuator, anddrive the correction lens frame 54 in the yaw direction with respect tothe moving frame 53 by electromagnetic force.

As shown in FIGS. 1 and 16A, the first position detection sensor 47 adetects the position of the correction lens frame 54 in the pitchdirection with respect to the moving frame 53. The second positiondetection sensor 47 b detects the position of the correction lens frame54 in the yaw direction with respect to the moving frame 53. The firstposition detection sensor 47 a and the second position detection sensor47 b are Hall elements, for example. The first position detection sensor47 a is disposed near the first magnet 54 a. The second positiondetection sensor 47 b is disposed near the second magnet 54 b.

A movement detection sensor (not shown), such as a gyro sensor, isinstalled in the interchangeable lens unit 2. The correction controller48 controls the correction drive unit 46 on the basis of the detectionresult of a position detection sensor 47 and the detection result of amovement detection sensor.

The method for suppressing blurring of the subject image may beelectronic blur correction in which blurring that appears in an image iscorrected on the basis of image data outputted from the imaging sensor11. The method for suppressing blurring of the subject image may also bea sensor shift method in which the imaging sensor 11 is driven in aplane that is perpendicular to the optical axis AX.

(6) Lens Controller 40

As shown in FIG. 1, the lens controller 40 has a CPU (not shown), a ROM(not shown), and a memory 40 a, and can carry out various functions byusing the CPU to execute programs stored in the ROM. For instance, thelens controller 40 is capable of detecting that the third lens supportframe 55 is in its home position on the basis of the detection result ofthe photosensor 67.

The memory 40 a is a nonvolatile memory, and can hold stored informationeven when the power supply has been halted. Information related to theinterchangeable lens unit 2 (lens information), for example, is held inthe memory 40 a.

The lens controller 40 further has a counter 40 b. The counter 40 bcounts the number of drive pulses of the focus motor 64. The lenscontroller 40 is capable of identifying the position of the third lensgroup G3 in the optical axis direction by counting the number of drivepulses of the focus motor 64 from a state in which the third lenssupport frame 55 is in its home position.

Planar Positional Relations of Various Members

The planar positional relations of the constituent members of theinterchangeable lens unit 2 will now be described in greater detailthrough reference to FIG. 20.

As shown in FIG. 20, several of the constituent members included in theinterchangeable lens unit 2 are dispersively arranged over a plane whenviewed in the optical axis direction.

More specifically, the zoom motor 87 and the transmission mechanism 84are disposed at positions that do not overlap the focus motor 64, thelens-side contact unit 91, the electrical board 92, the aperture drivemotor 62 a, the correction drive unit 46 (the first magnet 54 a, thesecond magnet 54 b, the first coil 46 a, and the second coil 46 b), thefocusing main shaft 58, the focusing sub-shaft 59, or the restrictingshaft 49 b when viewed in the optical axis direction.

The focus motor 64 is disposed at a position that does not overlap thezoom motor 87, the transmission mechanism 84, the lens-side contact unit91, the electrical board 92, the aperture drive motor 62 a, thecorrection drive unit 46, the focusing main shaft 58, the focusingsub-shaft 59, or the restricting shaft 49 b when viewed in the opticalaxis direction.

The lens-side contact unit 91 is disposed at a position that does notoverlap the zoom motor 87, the transmission mechanism 84, the focusmotor 64, the focusing main shaft 58, the focusing sub-shaft 59, or therestricting shaft 49 b when viewed in the optical axis direction. To putthis the other way, at least part of the lens-side contact unit 91overlaps the electrical board 92, the aperture drive motor 62 a and thecorrection drive unit 46 when viewed in the optical axis direction.

The electrical board 92 is disposed at a position that does not overlapthe zoom motor 87, the transmission mechanism 84, the focus motor 64,the focusing main shaft 58, or the focusing sub-shaft 59 when viewed inthe optical axis direction. To put this the other way, at least part ofthe electrical board 92 overlaps the lens-side contact unit 91, theaperture drive motor 62 a, the correction drive unit 46, and therestricting shaft 49 b when viewed in the optical axis direction.

The aperture drive motor 62 a is disposed at a position that does notoverlap the zoom motor 87, the transmission mechanism 84, the focusmotor 64, the correction drive unit 46, the focusing main shaft 58, thefocusing sub-shaft 59, or the restricting shaft 49 b when viewed in theoptical axis direction. To put this the other way, at least part of theaperture drive motor 62 a overlaps the lens-side contact unit 91 and theelectrical board 92 when viewed in the optical axis direction.

The correction drive unit 46 is disposed at a position that does notoverlap the zoom motor 87, the transmission mechanism 84, the focusmotor 64, the aperture drive motor 62 a, the focusing main shaft 58, thefocusing sub-shaft 59, or the restricting shaft 49 b when viewed in theoptical axis direction. To put this the other way, at least part of thecorrection drive unit 46 overlaps the lens-side contact unit 91 and theelectrical board 92 when viewed in the optical axis direction.

The focusing main shaft 58 and the focusing sub-shaft 59 are disposed atpositions that do not overlap the zoom motor 87, the transmissionmechanism 84, the focus motor 64, the lens-side contact unit 91, theelectrical board 92, the aperture drive motor 62 a, the correction driveunit 46, or the restricting shaft 49 b when viewed in the optical axisdirection.

The restricting shaft 49 b is disposed at a position that does notoverlap the zoom motor 87, the transmission mechanism 84, the focusmotor 64, the lens-side contact unit 91, the aperture drive motor 62 a,the correction drive unit 46, the focusing main shaft 58, or thefocusing sub-shaft 59 when viewed in the optical axis direction. To putthis the other way, restricting shaft 49 b overlaps the electrical board92 when viewed in the optical axis direction.

As described above, the interchangeable lens unit 2 can be made morecompact (and thinner in particular) by dispersively arranging several ofthe constituent members included in the interchangeable lens unit 2 overa plane.

Also, the aperture drive motor 62 a is disposed at a position that doesnot overlap the correction drive unit 46 (discussed below) when viewedin the optical axis direction. Therefore, any magnetic flux that leaksfrom the correction drive unit 46 will have less effect on the aperturedrive motor 62 a, so the operation of the aperture unit 62 can bestabilized while the interchangeable lens unit 2 is configured to bemade more compact.

The phrase “when viewed in the optical axis direction” means “whenviewed in a direction parallel to the optical axis in a state in whichother members have been removed so that at least members whosepositional relation is to be compared can be seen.” Therefore,regardless of whether or not the various members can be seen from theoutside of the interchangeable lens unit 2, the above-mentionedpositional relations may be determined by taking out just the members tobe compared.

Camera Body 3

The simplified configuration of the camera body 3 will be describedthrough reference to FIGS. 1 to 3A and 3B. As shown in FIGS. 1 to 3A and3B, the camera body 3 has a housing 3 a, the body mount 4, an interfaceunit 39, an image acquisition component 35, an image display component36, a viewfinder component 38, a body controller 10, and a battery 22.The camera body 3 does not have a quick-return mirror installed betweenthe body mount 4 and the imaging sensor 11.

(1) Housing 3 a

The housing 3 a constitutes the outer shell of the camera body 3. Asshown in FIGS. 3A and 3B, the body mount 4 is provided to the front faceof the housing 3 a. The interface unit 39 is provided to the rear andtop faces of the housing 3 a. More specifically, the rear face of thehousing 3 a is provided with a display component 20, a power switch 25,a mode selector dial 26, a cross key 27, a menu setting button 28, a setbutton 29, an imaging mode button 34, and a moving picture imagingbutton 24. The top face of the housing 3 a is provided with a shutterbutton 30.

(2) Body Mount 4

The lens mount 95 of the interchangeable lens unit 2 is mounted to thebody mount 4. The body mount 4 has a bayonet (not shown) that engageswith the bayonet 95 a of the lens mount 95. Also, the body mount 4 has abody-side contact unit (not shown). In a state in which the lens mount95 has been mounted to the body mount 4, the contacts of the lens-sidecontact unit 91 are in contact with the contacts of the body-sidecontact unit. In this state, the camera body 3 is able to send andreceive data to and from the interchangeable lens unit 2 via the bodymount 4 and the lens mount 95. For instance, the body controller 10(discussed below) sends a control signal such as an exposuresynchronization signal through the body mount 4 and the lens mount 95 tothe lens controller 40.

(3) Interface Unit 39

As shown in FIGS. 3A and 3B, the interface unit 39 has various interfacemembers that allow the user to input operation information. For example,the power switch 25 is used to turn on and off the power to the digitalcamera 1 or the camera body 3. When the power switch 25 is switched on,power is supplied to the various components of the camera body 3 and theinterchangeable lens unit 2.

The mode selector dial 26 is used to switch the operating mode between astill picture imaging mode, a moving picture imaging mode, areproduction mode, and so forth., and so forth. The user turns the modeselector dial 26 to switch the operating mode of the digital camera 1.When the still picture imaging mode is selected with the mode selectordial 26, the operating mode is switched to the still picture imagingmode. When the moving picture imaging mode is selected with the modeselector dial 26, the operating mode is switched to the moving pictureimaging mode. In the moving picture imaging mode, basically movingpicture imaging is possible. When the reproduction mode is selected withthe mode selector dial 26, the operating mode is switched to thereproduction mode, allowing the captured image to be displayed on thedisplay component 20.

The cross key 27 is used to select the left, right, up, and downdirections. The cross key 27 can be used to select the desired menu fromvarious menu screens displayed on the display component 20, for example.

The menu setting button 28 is used for setting the various operations ofthe digital camera 1. The set button 29 is used for executing theoperations of the various menus.

The moving picture imaging button 24 is used for starting and stoppingthe capture of moving pictures. Regardless of the setting of the modeselector dial 26, when the moving picture imaging button 24 is pressed,the operating mode is forcibly changed to the moving picture imagingmode and moving picture imaging begins. When this moving picture imagingbutton 24 is pressed during the capture of a moving picture, the movingpicture imaging ends and the operating mode is switched to the oneselected on the mode selector dial 26. For example, if the still pictureimaging mode has been selected with the mode selector dial 26 when themoving picture imaging button 24 is pressed, the operating mode isautomatically switched to the still picture imaging mode after themoving picture imaging button 24 is pressed again.

The shutter button 30 is pressed by the user to capture an image. Whenthe shutter button 30 is pressed, a timing signal is outputted to a bodycontroller 10. The shutter button 30 is a two-stage switch that can bepressed half-way down or all the way down. Light metering and rangingare commenced when the user presses the button half-way down. When theuser presses the shutter button 30 all the way down in a state in whichthe shutter button 30 has been pressed half-way down, a timing signal isoutputted, and image data is acquired by the image acquisition component35.

(4) Image Acquisition Component 35

The image acquisition component 35 mainly has a CCD (charge coupleddevice) or other such imaging sensor 11 (an example of an imagingelement) that performs opto-electric conversion, a shutter unit 33 thatadjusts the exposure state of the imaging sensor 11, a shuttercontroller 31 that controls the drive of the shutter unit 33 on thebasis of a control signal from the body controller 10, and an imagingsensor drive control component 12 that controls the operation of theimaging sensor 11.

The imaging sensor 11 converts the optical image formed by the opticalsystem O into image data. The imaging sensor 11 can be, for example, aCCD (charge coupled device) or a CMOS (complementary metal oxidesemiconductor) sensor. The imaging sensor 11 outputs image data on thebasis of a timing signal generated by the imaging sensor drive controlcomponent 12.

The shutter controller 31 controls a shutter drive motor 32 on the basisof a control signal sent from the body controller 10. For example, theshutter unit 33 is charged by the shutter drive motor 32.

The auto-focus method that is employed in this embodiment is a contrastdetection method. The use of a contrast detection method affordshigh-precision focal adjustment. However, some other method (such as aphase difference detection method) may be used instead as the auto-focusmethod.

(5) Body Controller

The body controller 10 controls the various components of the digitalcamera 1. More specifically, the body controller 10 is equipped with aCPU (not shown), a ROM (not shown), and a RAM (not shown). The programsheld in the ROM are executed by the CPU, allowing the body controller 10to perform a variety of functions. For instance, the body controller 10has the function of detecting that the interchangeable lens unit 2 hasbeen mounted to the camera body 3, or the function of acquiring from theinterchangeable lens unit 2 any focal distance information or other suchinformation that is necessary for controlling the digital camera 1.

The body controller 10 is able to receive signals from the power switch25, the shutter button 30, the mode selector dial 26, the cross key 27,the menu setting button 28, and the set button 29. Various informationrelated to the camera body 3 is held in a memory 10 a inside the bodycontroller 10. The memory 10 a is a nonvolatile memory, and is capableof holding stored information even when the power supply has beenhalted.

Also, the body controller 10 periodically produces a verticalsynchronization signal, and produces an exposure synchronization signalon the basis of the vertical synchronization signal and in parallel withthe production of the vertical synchronization signal. The bodycontroller 10 can produce an exposure synchronization signal because theexposure start timing and the exposure stop timing based on the verticalsynchronization signal have been ascertained beforehand. The bodycontroller 10 outputs a vertical synchronization signal to a timinggenerator (not shown), and outputs an exposure synchronization signal ata specific period to the lens controller 40 via the body mount 4 and thelens mount 95. The lens controller 40 acquires position informationabout the focus lens unit 75 in synchronization with the exposuresynchronization signal.

The imaging sensor drive control component 12 produces an electronicshutter drive signal and a read signal of the imaging sensor 11 at aspecific period on the basis of the vertical synchronization signal. Theimaging sensor drive control component 12 drives the imaging sensor 11on the basis of the electronic shutter drive signal and the read signal.That is, the imaging sensor 11 reads to a vertical transfer component(not shown) the image data produced by numerous opto-electricalconversion elements (not shown) had by the imaging sensor 11, accordingto the read signal.

The body controller 10 also controls the focus adjusting unit 72 via thelens controller 40.

The image data outputted from the imaging sensor 11 is sent from ananalog signal processing component 13 and successively processed by anA/D converting component 14, a digital signal processing component 15, abuffer memory 16, and an image compressing component 17. The analogsignal processing component 13 subjects the image data outputted fromthe imaging sensor 11 to gamma processing or other such analog signalprocessing. The A/D converting component 14 converts the analog signaloutputted from the analog signal processing component 13 into a digitalsignal. The digital signal processing component 15 subjects the imagedata converted into a digital signal by the A/D converting component 14to digital signal processing such as noise elimination or contourenhancement. The buffer memory 16 is a RAM (Random Access Memory), andtemporarily stores the image data. The image data stored in the buffermemory 16 is sent to and processed by first the image compressingcomponent 17 and then an image recording component 18. The image datastored in the buffer memory 16 is read at a command from an imagerecording control component 19 and sent to the image compressingcomponent 17. The image data sent to the image compressing component 17is compressed according to a command from the image recording controlcomponent 19. This compression adjusts the image data to a smaller datasize than that of the original data. An example of the method forcompressing the image data is the JPEG (Joint Photographic ExpertsGroup) method in which compression is performed on each frame of imagedata. After this, the compressed image data is recorded by the imagerecording control component 19 to the image recording component 18. Whena moving picture is recorded, JPEG can be used to compress a pluralityof sets of image data, in which the image data is compressed the imagedata for each frame. Alternatively, an H.264/AVC method can also beused, in which compression is performed on image data for a plurality offrames all at once.

The image recording component 18 produces a still picture file or movingpicture file that is associated with specific information to be recordedwith the image data, on the basis of a command from the image recordingcontrol component 19. The image recording component 18 then records thestill picture file or moving picture file on the basis of a command fromthe image recording control component 19. The image recording component18 is a removable memory and/or an internal memory, for example. Thespecific information to be recorded along with the image data includesthe date and time the image was captured, focal distance information,shutter speed information, aperture value information, and imaging modeinformation. Still picture files are in Exif® format or a format similarto Exif® format, for example. Moving picture files are in H.264/AVCformat or a format similar to H.264/AVC format, for example.

(6) Image Display Component

The image display component 36 has the display component 20 and an imagedisplay control component 21. The display component 20 is a liquidcrystal monitor, for example. The display component 20 displays theimage data recorded to the image recording component 18 or the buffermemory 16 as a visible image on the basis of a command from the imagedisplay control component 21. Possible display modes with the displaycomponent 20 are a display mode in which just the image data isdisplayed as a visible image, and a display mode in which the image dataand information about the time of image capture are displayed as visibleimages.

(7) Viewfinder Component

The viewfinder component 38 has a liquid crystal viewfinder 8 thatdisplays images acquired by the imaging sensor 11, and a viewfindereyepiece window 9 provided to the rear face of the housing 3 a. The usercan see the image displayed on the liquid crystal viewfinder 8 bylooking through the viewfinder eyepiece window 9.

(8) Battery

The battery 22 supplies electrical power to the various components ofthe camera body 3, and also supplies power to the interchangeable lensunit 2 via the lens mount 95. In this embodiment, the battery 22 is arechargeable cell. The battery 22 may also be a dry cell, or may be anexternal power supply with which power is supplied from the outsidethrough a power cord.

Operation of Digital Camera

The operation of the digital camera 1 will now be described.

(1) Imaging Mode

This digital camera 1 has two imaging modes. More specifically, thedigital camera 1 has a viewfinder imaging mode in which the user looksat the subject through the viewfinder eyepiece window 9, and a monitorimaging mode in which the user looks at the subject on the displaycomponent 20.

In viewfinder imaging mode, the image display control component 21drives the liquid crystal viewfinder 8, for example. As a result, animage of the subject (a so-called through-image) acquired by the imagingsensor 11 is displayed in the liquid crystal viewfinder 8.

In monitor imaging mode, the image display control component 21 drivesthe display component 20, for example, and a real-time image of thesubject is displayed on the display component 20. Switching betweenthese two imaging modes is configured to be accomplished with theimaging mode button 34.

(2) Still Picture Imaging

When the user presses the shutter button 30 all the way down, a commandis sent from the body controller 10 to the lens controller 40 so thatthe aperture value of the optical system O will be set to the aperturevalue calculated on the basis of the light metering output of theimaging sensor 11. The aperture drive control component 42 is thencontrolled by the lens controller 40, and the aperture unit 62 isstopped down to the indicated aperture value. Simultaneously with theaperture value indication, a drive command is sent from the imagingsensor drive control component 12 to the imaging sensor 11, and acommand to drive the shutter unit 33 is sent. The imaging sensor 11 isexposed by the shutter unit 33 for the length of time of the shutterspeed calculated on the basis of the light metering output from theimaging sensor 19.

When image capture processing has been executed and imaging is finished,the body controller 10 sends a control signal to the image recordingcontrol component 19. The image recording component 18 records imagedata to an internal memory and/or a removable memory on the basis of acommand from the image recording control component 19. The imagerecording component 18 records imaging mode information (whetherauto-focus imaging mode or manual focus imaging mode) along with imagedata to an internal memory and/or a removable memory on the basis of thecommand from the image recording control component 19.

Upon completion of the exposure, the imaging sensor drive controlcomponent 12 reads the image data from the imaging sensor 11, and afterspecific image processing, image data is outputted to the image displaycontrol component 21 via the body controller 10. Consequently, acaptured image is displayed on the display component 20.

Also, upon completion of exposure, the shutter unit 33 is reset to itsinitial position by the body controller 10. Also, a command is issuedfrom the body controller 10 to the lens controller 40, directing theaperture drive control component 42 to reset the aperture unit 62 to itsopen position, and reset commands are issued by the lens controller 40to the various units. Upon completion of the resetting, the lenscontroller 40 notifies the body controller 10 of reset completion. Thebody controller 10 confirms that the shutter button 30 has not beenpressed after the receipt of reset completion information from the lenscontroller 40 and after a series of processing following exposure hasbeen completed, and ends the imaging sequence.

(3) Moving Picture Imaging

The digital camera 1 also has the function of capturing moving pictures.In moving picture imaging mode, image data is produced by the imagingsensor 11 at a specific period, and the image data thus produced isutilized to continuously carry out auto-focusing by contrast detectionmethod. In moving picture imaging mode, a moving picture is recorded tothe image recording component 18 when the shutter button 30 is pressedor when the moving picture imaging button 24 is pressed, and recordingof the moving picture stops when the shutter button 30 or the movingpicture imaging button 24 is pressed again.

Operation of Interchangeable Lens Unit 2

The operation of the interchangeable lens unit 2 will now be described.

(1) When Power is On

When the power switch 25 is switched on, power is supplied to thevarious components of the camera body 3 and the interchangeable lensunit 2. When power is supplied to the interchangeable lens unit 2, theinterchangeable lens unit 2 is driven by the zoom motor 87 from itsstowed state to its initial imaging state. More specifically, the zoommotor 87 is controlled by the lens controller 40 so that the cam frame80 will rotate by a specific angle with respect to the fixed frame 50.

When the zoom driveshaft 87 a of the zoom motor 87 rotates, the camframe 80 rotates with respect to the fixed frame 50 via the firsttransmission gear 85, the second transmission gear 86, and the gearcomponent 82.

When the cam frame 80 rotates with respect to the fixed frame 50, theguide cam followers 83 are guided by the guide cam grooves 50 b. As aresult, the cam frame 80 moves to the subject side while rotating withrespect to the fixed frame 50.

Also, when the cam frame 80 rotates with respect to the fixed frame 50,the first lens support frame 51 moves along with the cam frame 80 in theoptical axis direction. More specifically, since the rectilinearprotrusions 51 b are guided in the optical axis direction by therectilinear grooves 50 a, even though the cam frame 80 rotates withrespect to the fixed frame 50, the first lens support frame 51 does notrotate with respect to the fixed frame 50. Therefore, as the cam frame80 rotates, the inner peripheral cam followers 51 d of the first lenssupport frame 51 are guided by the outer peripheral cam grooves 83 b ofthe cam frame 80. As a result, the first lens support frame 51 moves tothe subject side with respect to the cam frame 80. That is, the firstlens support frame 51 is deployed from the fixed frame 50 to the subjectside without rotating with respect to the fixed frame 50.

Furthermore, when the cam frame 80 rotates with respect to the fixedframe 50, the second lens support frame 69 moves along with the camframe 80 in the optical axis direction. More specifically, since therotation of the moving frame 53 with respect to the fixed frame 50 isrestricted by the rectilinear guide plates 56 a of the fourth lenssupport frame 56, the moving frame 53 does not rotate with respect tothe fixed frame 50 even though the cam frame 80 does rotate with respectto the fixed frame 50. Therefore, as the cam frame 80 rotates, the camfollowers 53 e to 53 g of the moving frame 53 are guided by the innerperipheral cam grooves 83 a. At this point, since the cam followers 53 eto 53 g are guided by the region extending in the peripheral directionof the inner peripheral cam grooves 83 a, the moving frame 53 does notmove in the optical axis direction with respect to the cam frame 80.That is, the moving frame 53 moves to the subject side along with thecam frame 80 with respect to the fixed frame 50.

Thus, as shown in FIGS. 6B and 7B, the interchangeable lens unit 2 goesfrom its stowed state to its initial imaging state. In this embodiment,the optical system O is at the wide angle end when the interchangeablelens unit 2 is in its initial imaging state.

(2) During Zooming

The focal distance of the interchangeable lens unit 2 is adjustablebetween the wide angle end and the telephoto end by operating the zoomlever 89. More specifically, when the zoom lever 89 is operated to thetelephoto side, the zoom lever detect component 90 detects thisoperation of the zoom lever 89, and the lens controller 40 controls thezoom motor 87 on the basis of the detection result of the zoom leverdetect component 90.

When the zoom driveshaft 87 a of the zoom motor 87 rotates, the camframe 80 rotates with respect to the fixed frame 50 via the transmissionmechanism 84. The cam frame 80 rotates from the wide angle end to thetelephoto end of the interchangeable lens unit 2 without moving in theoptical axis direction with respect to the fixed frame 50. When the camframe 80 rotates with respect to the fixed frame 50, the innerperipheral cam followers 51 d are guided by the outer peripheral camgrooves 83 b, and the first lens support frame 51 moves in the opticalaxis direction with respect to the fixed frame 50 according to the shapeof the outer peripheral cam grooves 83 b. In this embodiment, as shownin FIGS. 6C and 7C, the first lens support frame 51 moves to the imageplane side with respect to the fixed frame 50, from the wide angle endto the telephoto end of the interchangeable lens unit 2.

Also, when the cam frame 80 rotates with respect to the fixed frame 50,the cam followers 53 e to 53 g of the moving frame 53 are guided by theinner peripheral cam grooves 83 a, and the second lens support frame 69moves in the optical axis direction with respect to the fixed frame 50according to the shape of the inner peripheral cam grooves 83 a. At thispoint, since the rotation of the moving frame 53 is restricted by therectilinear guide plates 56 a of the fourth lens support frame 56, themoving frame 53 moves in the optical axis direction without rotatingwith respect to the fixed frame 50. In this embodiment, as shown inFIGS. 6C and 7C, the second lens support frame 69 moves to the subjectside with respect to the fixed frame 50, from the wide angle end to thetelephoto end of the interchangeable lens unit 2.

When the second lens support frame 69 moves to the subject side, the camframe 80 rotates with respect to the fixed frame 50. At this point, thegear component 82 of the cam frame 80 moves into the cut-out 53 d in themoving frame 53, and the gear component 82 passes through the cut-out 53d. Therefore, even though the gear component 82 is formed on the innerperipheral face of the cam frame 80, a large amount of movement of thesecond lens support frame 69 in the optical axis direction can beensured.

The focal distance of the interchangeable lens unit 2 thus changes tothe telephoto side according to how long the zoom lever 89 is operated.

The operation of the interchangeable lens unit 2 when the zoom lever 89is operated to the wide angle side is just the reverse of that when thezoom lever 89 is operated to the telephoto side, so it will not bedescribed in detail here.

Features of Interchangeable Lens Unit 2

The features of the interchangeable lens unit 2 are compiled below.

(1) As shown in FIG. 8B, the gear component 82 is disposed at asubstantially middle position of the main body 81 in the cam frame 80 inthe optical axis direction, so a space is formed between the gearcomponent 82 and the lens housing 2 a in the optical axis direction.More specifically, as shown in FIGS. 6A to 6C, in a state in which thecam frame 80 is closest to the base member 93, a holding space S isensured between the gear component 82 and the base member 93 in theoptical axis direction. Therefore, this holding space S can be moreeffectively utilized than when the gear component 82 is formed at theend of the cam frame 80 on the lens housing 2 a side. For example, sinceother constituent members can be disposed in this holding space S, thevarious members can be disposed more efficiently.

Furthermore, the member of the zoom drive unit 45 that meshes with thegear component 82 (that is, the first transmission gear 85) can be madesmaller in the optical axis direction than when the gear component 82 isformed at the end of the cam frame 80 on the opposite side from the lenshousing 2 a.

Thus, with this interchangeable lens unit 2, the various members can bedisposed more efficiently and the size of the unit can be reduced.

(2) As shown in FIGS. 12B and 13A, the zoom motor 87 and thetransmission mechanism 84 are disposed on the inner peripheral side ofthe cam frame 80, and the zoom motor 87 and the transmission mechanism84 go into the holding space S. Here, the phrase “the zoom motor 87 goesinto the holding space S” means that at least part of the zoom motor 87is disposed between the gear component 82 and the base member 93 in theoptical axis direction. Also, the phrase “the transmission mechanism 84goes into the holding space S” means that at least part of thetransmission mechanism 84 is disposed between the gear component 82 andthe base member 93 in the optical axis direction.

(3) As shown in FIG. 6A, part of the moving frame 53 is disposed in theholding space S in a state in which the cam frame 80 is closest to thelens housing 2 a in the optical axis direction. Therefore, with thisinterchangeable lens unit 2, so the holding space S can be utilized moreeffectively and the size of the unit can be further reduced.

Also, the gear component 82 of the cam frame 80 moves into the cut-out53 d while the moving frame 53 is being guided in the optical axisdirection by the cam frame 80. Therefore, even though part of the movingframe 53 goes into the holding space S, the moving frame 53 is preventedfrom interfering with the cam frame 80, and a larger range of movementcan be ensured for the moving frame 53.

Furthermore, since the second gear component 82 b is disposed so as tomove steadily from the first gear component toward the base member 93,when the moving frame 53 is guided by the cam frame 80 in the opticalaxis direction, the gear component 82 passes more easily through thecut-out 53 d in the moving frame 53. Consequently, the length of thegear component 82 in the peripheral direction is able to be increasedwhile a larger range of movement of the moving frame 53 is ensured.

(4) As shown in FIG. 8B, part of the inner peripheral cam grooves 83 aof the cam frame 80 is disposed between the gear component 82 and thebase member 93. Therefore, the space on the image plane side of the gearcomponent 82 created by disposing the gear component 82 at a middleposition in the optical axis direction can be effectively utilized.

(5) As shown in FIG. 9A, since the inside radius R1 of the bottom faceof the inner peripheral cam grooves 83 a is greater than the root radiusR2 of the gear component 82, even when the layout is such that the innerperipheral cam grooves 83 a and the gear component 82 overlap, the shapeof the inner peripheral cam grooves 83 a can be ensured within thesmallest required range. Therefore, even though the gear component 82 isprovided to the inner peripheral face of the cam frame 80, the camgrooves will tend not to be subject to restrictions, so design latitudeis compromised less.

Also, since the root radius R2 of the gear component 82 is less than theinside radius R3 of the main body 81, the first transmission gear 85 isprevented from interfering with the inner peripheral face of the mainbody component 81. Also, even if the outer peripheral cam groove 83 boverlaps the gear component 82, it will still be easy to ensure theproper thickness of the cam frame 80, so there will be less decrease inthe strength of the cam frame 80.

(6) As shown in FIG. 8A, the fixed components 50 e of the base member 93and the fixed frame 50 are disposed between the guide cam grooves 50 bin the peripheral direction, so the fixed frame 50 can be shorter in theoptical axis direction, and the interchangeable lens unit 2 can be mademore compact.

(7) As shown in FIG. 8A, since the zoom lever 89 and the focus lever 98are disposed at positions farther away from the base member 93 than theguide cam grooves 50 b in the optical axis direction, when the variousmembers are assembled on the fixed frame 50, they will not interferewith the zoom lever 89 and the focus lever 98. Therefore, even thoughthe zoom lever 89 and the focus lever 98 are provided to theinterchangeable lens unit 2, the interchangeable lens unit 2 is no moredifficult to assemble.

Second Embodiment

In the first embodiment given above, the zoom lever 89 and the focuslever 98 are used to change the focal distance and adjust the focus.However, changing the focal distance may be accomplished using a zoomring, and focusing may be accomplished using a focus ring. Aninterchangeable lens unit 302 pertaining to a second embodiment will nowbe described, using a zoom ring as an example.

Those components that have substantially the same function as those inthe first embodiment above will be numbered the same and will not bedescribed in detail again.

The interchangeable lens unit 302 shown in FIG. 21 is equipped with azoom ring unit 388. The zoom ring unit 388 has a stop ring 388 a (anexample of a restricting member) and a zoom ring 389 (an example of aninterface member). In other words, the stop ring 388 a is an annularmember, and is mounted to the end of a fixed frame 350 on the subjectside. The stop ring 388 a is disposed on the opposite side of the fixedframe 350 from the base member 93. The zoom ring 389 is an annularmember and is sandwiched between the fixed frame 350 and the stop ring388 a. The zoom ring 389 is rotatably supported by the fixed frame 350and the stop ring 388 a, and its movement in the optical axis directionis restricted with respect to the fixed frame 350.

Also, a rotation detector 388 b is provided on the inner peripheral sideof the zoom ring 389. The rotation detector 388 b can detect therotation direction and rotation angle of the zoom ring 389. This allowsthe lens controller 40 to ascertain the direction and amount in whichthe zoom ring 389 is operated. The zoom ring 389 is disposed more to thesubject side than the zoom motor 87.

The focal distance can also be adjusted with this constitution.

The zoom ring 389 may be rotatably supported by the stop ring 388 aand/or the fixed frame 350.

Other Embodiments

The technology disclosed herein is not limited to the embodiments givenabove, and various modifications and variations are possible withoutdeparting from the gist of the invention.

Those components that have substantially the same function as those inthe first and second embodiments above will be numbered the same andwill not be described in detail again.

(1) In the above embodiments, an imaging device was described by usingthe digital camera 1 as an example, but the imaging device is notlimited to being the digital camera 1. For instance, the digital camera1 can perform still picture imaging and moving picture imaging, but theimaging device may be one that performs only still picture imaging, orone that performs only moving picture imaging.

(2) In the above embodiments, a lens barrel was described using theinterchangeable lens units 2 and 302 as an example, but the lens barrelis not limited to being the interchangeable lens unit 2 or 302. Forexample, the lens barrel may be one that is used in an imaging devicethat has an integrated construction, rather than employing aninterchangeable lens unit.

(3) In the above embodiments, a first actuator is described using thezoom motor 87 as an example, but the first actuator is not limited tobeing the zoom motor 87. For example, the first actuator may be somemotor other than one used for zoom adjustment. Also, the first actuatoris not limited to being a DC motor, and may be some other type of motor(such as a stepping motor).

Also, a second actuator is described using the focus motor 64 as anexample, but the second actuator is not limited to being the focus motor64. For example, the second actuator may be some motor other than oneused for focus adjustment. Also, the second actuator is not limited tobeing a stepping motor, and may be some other type of motor (such as aDC motor).

Furthermore, the first actuator may be an actuator other than a motor,such as a piezoelectric actuator. More specifically, as shown in FIG.22A, a piezoelectric actuator 187 is mounted to the lens housing 2 a(more precisely, the fourth lens support frame 56). The lengthwisedirection L of the piezoelectric actuator 187 is different from theoptical axis direction. More precisely, as shown in FIG. 22A, thelengthwise direction L of the piezoelectric actuator 187 is disposedsubstantially parallel to a plane that is perpendicular to the opticalaxis direction (that is, the paper plane in FIG. 22A), just as with therotational axis E1 of the zoom motor 87.

The piezoelectric actuator 187 is in contact with a second transmissiongear 186 of the transmission mechanism 84. The second transmission gear186 corresponds to the above-mentioned second transmission gear 86. Asshown in FIG. 22B, when voltage is applied to the piezoelectric actuator187, the piezoelectric actuator 187 is displaced in the directionindicated by the arrow. This displacement of the piezoelectric actuator187 imparts torque to the second transmission gear 186, causing thesecond transmission gear 186 to rotate around the rotational axis E3. Asa result, the cam frame 80 rotates via the first transmission gear 85.

Also, the configuration shown in FIG. 22C is possible for thetransmission mechanism 84 when the piezoelectric actuator 187 is used.More specifically, as shown in FIG. 22C, the member that is in contactwith the piezoelectric actuator 187 may be a rotating member 286. Thedisplacement of the piezoelectric actuator 187 imparts torque to therotating member 286, causing the rotating member 286 to rotate. Therotation of the rotating member 286 is transmitted through anintermediate transmission gear 288 to the first transmission gear 85,and the cam frame 80 rotates as a result.

(4) In the above embodiments, a transmission mechanism is describedusing the transmission mechanism 84 as an example, but the transmissionmechanism is not limited to being the transmission mechanism 84. As longas the transmission mechanism has a configuration in which drive forceis transmitted from the driveshaft of a first actuator to a secondframe, the transmission mechanism may have some other configuration. Forinstance, the transmission mechanism 84 may have a spur gear or anothersuch member besides the first transmission gear 85 and the secondtransmission gear 86, or the structure of the transmission mechanism 84may be simpler than the structure discussed above.

Also, a first transmission gear member is described using the firsttransmission gear 85 as an example, but the first transmission gearmember is not limited to being the first transmission gear 85. Forexample, the lens barrel may be made more compact even if the rotationalaxis E2 of the first transmission gear 85 is not parallel to the opticalaxis direction.

Also, a second transmission gear member is described using the secondtransmission gear 86 as an example, but the second transmission gearmember is not limited to being the second transmission gear 86. Forexample, the lens barrel may be made more compact even if the rotationalaxis E3 of the second transmission gear 86 is not parallel to theoptical axis direction.

(5) The rotational axis E3 of the second transmission gear 86 isinclined by an angle of θ4, which is substantially the same as the leadangle of the second intermediate gear 86 b, with respect to a plane thatis perpendicular to the optical axis direction, but the rotational axisE3 of the second transmission gear 86 need not be inclined with respectto a plane that is perpendicular to the optical axis direction.

Also, the output gear 87 b of the zoom motor 87 is disposed between thefirst intermediate gear 86 a of the second transmission gear 86 and thebase member 93, but the zoom motor 87 and the second transmission gear86 are not limited to having this layout.

(6) In the above embodiments, the lengthwise direction of the firstactuator is different from the optical axis direction, but thelengthwise direction of the first actuator may be the same as theoptical axis direction. Also, the lengthwise direction of the firstactuator is parallel to a plane that is perpendicular to the opticalaxis direction, but the lengthwise direction of the first actuator maybe inclined with respect to a plane that is perpendicular to the opticalaxis direction.

(7) In the above embodiments, a first frame is described using the basemember 93 as an example, but the first frame is not limited to being thebase member 93. For example, the first frame may be constituted by asingle member.

Also, in the above embodiments, a second frame is described using thecam frame 80 as an example, but the second frame is not limited to beingthe cam frame 80. For example, the cam frame 80 moved in the opticalaxis direction with respect to the base member 93, but the second framemay not move in the optical axis direction with respect to the firstframe.

(8) In the above embodiments, the transmission mechanism 84 transmittedthe rotation of the zoom driveshaft 87 a to the gear component 82 of thecam frame 80 after first reducing its speed, but the transmissionmechanism 84 may instead transmit the rotation of the zoom driveshaft 87a to the gear component 82 without reducing its speed.

(9) In the above embodiments, an interface member was described usingthe zoom lever 89, the focus lever 98, and the zoom ring 389 asexamples, but the interface member may be a focus ring used in adjustingthe focus.

(10) In the above embodiments, the zoom motor 87 is disposed at aposition that does not overlap the lens-side contact unit 91 or theelectrical board 92 when viewed in the optical axis direction, but aslong as the interchangeable lens unit 2 is able to be made more compact,the zoom motor 87 may overlap the lens-side contact unit 91 and theelectrical board 92 when viewed in the optical axis direction.

Also, the focus motor 64 is disposed at a position that does not overlapthe lens-side contact unit 91 or the electrical board 92 when viewed inthe optical axis direction, but as long as the interchangeable lens unit2 is able to be made more compact, the focus motor 64 may overlap thelens-side contact unit 91 and the electrical board 92 when viewed in theoptical axis direction.

(11) In the above embodiments, the rotational axis E4 of the focusdriveshaft 64 a of the focus motor 64 was parallel to the optical axisdirection, but the rotational axis E4 of the focus driveshaft 64 a maybe inclined with respect to the optical axis direction.

Also, the focus driveshaft 64 a has a lead screw, and the third lenssupport frame 55 has the rack 55 c. However, the configuration fordriving the third lens support frame 55 is not limited to thisconfiguration.

(12) The zoom motor 87 is disposed at a position that does not overlapthe correction drive unit 46 when viewed in the optical axis direction,but as long as the interchangeable lens unit 2 is able to be made morecompact, the zoom motor 87 may overlap the correction drive unit 46 whenviewed in the optical axis direction.

Also, the focus motor 64 is disposed at a position that does not overlapthe correction drive unit 46 when viewed in the optical axis direction,but as long as the interchangeable lens unit 2 is able to be made morecompact, the focus motor 64 may overlap the correction drive unit 46when viewed in the optical axis direction.

(13) In the above embodiments, a guide member is described using thefocusing main shaft 58 as an example, but the guide member is notlimited to being the focusing main shaft 58. Also, a rotationrestricting member is described using the focusing sub-shaft 59 as anexample, but the rotation restricting member is not limited to being thefocusing sub-shaft 59.

For example, the focusing main shaft 58 and the focusing sub-shaft 59are disposed at a position that does not overlap the zoom motor 87 whenviewed in the optical axis direction, but as long as the interchangeablelens unit 2 is able to be made more compact, the focusing main shaft 58and the focusing sub-shaft 59 may overlap the zoom motor 87 when viewedin the optical axis direction.

Also, the focusing main shaft 58 and the focusing sub-shaft 59 aredisposed at positions that does not overlap the focus motor 64 whenviewed in the optical axis direction, but as long as the interchangeablelens unit 2 is able to be made more compact, the focusing main shaft 58and the focusing sub-shaft 59 may overlap the focus motor 64 when viewedin the optical axis direction.

(14) In the above embodiments, a moving frame is described using themoving frame 53 as an example, but the moving frame is not limited tobeing the moving frame 53. For example, the moving frame 53 has theholder portion 53 c, but as long as interference between the focusingsub-shaft 59 and the moving frame 53 is able to be avoided with anotherconfiguration, the moving frame 53 need not have the holder portion 53c.

Also, the above-mentioned holder portion 53 c is a pouch-likecylindrical component that is closed at one end, but the holder portion53 c may instead be a simple cylindrical portion or a through-hole.

(15) In the above embodiments, the electrical board 92 is fixed to thefourth lens support frame 56, but the interchangeable lens unit 2 isalso able to be made more compact if the electrical board 92 is insteadfixed to the lens mount 95 or some other member.

Also, the zoom motor 87 is fixed to the fourth lens support frame 56,but the interchangeable lens unit 2 can also be made more compact if thezoom motor 87 is instead fixed to the lens mount 95 or some othermember. Similarly, the transmission mechanism 84 is supported by thefourth lens support frame 56, but the interchangeable lens unit 2 isalso able to be made more compact if the transmission mechanism 84 isinstead supported by the lens mount 95 or some other member.

Furthermore, the focusing main shaft 58 is fixed to the fourth lenssupport frame 56, but the focusing main shaft 58 may instead be fixed tosome other member.

(16) In the above embodiments, a shaft support member is described usingthe first support cover 57 as an example, but the shaft support memberis not limited to being the first support cover 57. The interchangeablelens unit 2 is also able to be made more compact if the first supportcover 57 has some other shape instead.

(17) The zoom motor 87 is disposed at a position that does not overlapthe aperture drive motor 62 a when viewed in the optical axis direction,but as long as the interchangeable lens unit 2 is able to be made morecompact, the zoom motor 87 may overlap the aperture drive motor 62 awhen viewed in the optical axis direction.

Also, the focus motor 64 is disposed at a position that does not overlapthe aperture drive motor 62 a when viewed in the optical axis direction,but as long as the interchangeable lens unit 2 is able to be made morecompact, the focus motor 64 may overlap the aperture drive motor 62 awhen viewed in the optical axis direction.

(18) The restricting shaft 49 b, which is an example of a restrictingshaft, is disposed at a position that does not overlap the aperture unit62 when viewed in the optical axis direction, but as long as theinterchangeable lens unit 2 is able to be made more compact, therestricting shaft 49 b may overlap the aperture unit 62 when viewed inthe optical axis direction.

(19) The cam follower 53 e, which is an example of a first cam follower,is disposed on the outer peripheral side of the zoom motor 87 whenviewed in the optical axis direction, but the interchangeable lens unit2 is also able to be made more compact if the cam follower 53 e is notdisposed on the outer peripheral side of the zoom motor 87 when viewedin the optical axis direction.

Also, the focus motor 64 is disposed between the cam follower 53 e andthe cam follower 53 f in the peripheral direction when viewed in theoptical axis direction, but the interchangeable lens unit 2 is also ableto be made more compact if the focus motor 64 is not disposed betweenthe cam follower 53 e and the cam follower 53 f in the peripheraldirection when viewed in the optical axis direction.

Furthermore, in the above embodiments, the central angle θ1 between thecam follower 53 e and the cam follower 53 f is greater than the centralangle θ2 between the cam follower 53 e and the cam follower 53 g, and isgreater than the central angle θ3 between the cam follower 53 f and thecam follower 53 g. However, the interchangeable lens unit 2 is also ableto be made more compact if the central angle θ1 is not greater than thecentral angles θ2 or θ3, such as when the central angles θ1 to θ3 arethe same.

(20) The moving frame 53 has the cut-out 53 d formed between the camfollowers 53 e and 53 f, and the focus motor 64 is disposed in thecut-out 53 d when viewed in the optical axis direction, but the focusmotor 64 need not be disposed in the cut-out 53 d, and some other membermay instead be disposed in the cut-out 53 d.

Also, the gear component 82 of the cam frame 80 is configured to passthrough the cut-out 53 d while the moving frame 53 is being guided inthe optical axis direction by the cam frame 80, but the interchangeablelens unit 2 is also able to be made more compact if the outer size ofthe moving frame 53 is made smaller so as to avoid the gear component82.

(21) The rotational axis E1 of the zoom driveshaft 87 a of the zoommotor 87 is disposed substantially in the peripheral direction of thecam frame 80, but the zoom motor 87 is not limited to having thislayout. For example, the interchangeable lens unit 2 is also able to bemade more compact if the rotational axis E1 of the zoom driveshaft 87 ais not disposed in the peripheral direction of the cam frame 80.

(22) In the above embodiments, the gear component of a first frame isdescribed using the gear component 82 of the cam frame 80 as an example,but the gear component is not limited to being the gear component 82.For example, the gear component 82 has the first gear component 82 a andthe second gear component 82 b, but, for example the gear component 82may instead have just the first gear component 82 a, or just the secondgear component 82 b. Furthermore, the gear component 82 may have aportion other than the first gear component 82 a and the second gearcomponent 82 b.

Also, the position of the gear component 82 in the optical axisdirection is not limited to that in the above embodiments. As long asthe interchangeable lens unit 2 is able to be made more compact, thegear component 82 may be offset somewhat toward the image plane side orthe subject side from the middle position of the main body 81 in theoptical axis direction.

(23) In the above embodiments, a drive actuator is described using thezoom drive unit 45 as an example, but the drive actuator is not limitedto being the zoom drive unit 45. The drive actuator may have some otherconfiguration, as long as it rotationally drives the second frame withrespect to the first frame.

(24) In the above embodiments, the zoom motor 87 and the transmissionmechanism 84 go into the stowage space S, but as long as the stowagespace S is effectively utilized in some way, and as a result theinterchangeable lens unit 2 is able to be made more compact, the zoommotor 87 and the transmission mechanism 84 need not go into the stowagespace S.

(25) In the above embodiments, part of the moving frame 53 goes into thestowage space S in the stowed state in which the cam frame 80 is closestto the base member 93 in the optical axis direction, but as long as thestowage space S is effectively utilized in some way, and as a result theinterchangeable lens unit 2 is also able to be made more compact, thepart of the moving frame 53 need not go into the stowage space S.

(26) Part of one of the three inner peripheral cam grooves 83 a isdisposed between the gear component 82 and the base member 93, but aslong as the interchangeable lens unit 2 is able to be more compact, thecam groove need not be disposed between the gear component 82 and thebase member 93. Conversely, all of one of the inner peripheral camgrooves 83 a may be disposed between the gear component 82 and the basemember 93, or at least part of another inner peripheral cam groove 83 amay be disposed between the gear component 82 and the base member 93.

(27) In the above embodiments, the electrical board 92 is disposed onthe inner peripheral side of the cam frame 80 when viewed in the opticalaxis direction, but as long as the interchangeable lens unit 2 is ableto be made more compact, the electrical board 92 need not be disposed onthe inner peripheral side of the cam frame 80 when viewed in the opticalaxis direction. For example, part of the electrical board 92 may overlapthe cam frame 80 when viewed in the optical axis direction.

(28) In the above embodiments, the first coil 46 a and the second coil46 b are fixed on the image plane side of the moving frame 53, but mayinstead be fixed on the image plane side of the aperture unit 62. Inthis case, for example, the first coil 46 a and the second coil 46 b areconfigured to be disposed close to the first magnet 54 a and the secondmagnet 54 b, respectively, by cutting out the region of the moving frame53 that overlaps the first coil 46 a and the second coil 46 b in theoptical axis direction, allowing an electromagnetic actuator to beconstituted.

INDUSTRIAL APPLICABILITY

The lens barrel described above is configured to be made more compact,and is therefore useful in the field of imaging devices.

GENERAL INTERPRETATION OF TERMS

In understanding the scope of the present disclosure, the term“comprising” and its derivatives, as used herein, are intended to beopen ended terms that specify the presence of the stated features,elements, components, groups, integers, and/or steps, but do not excludethe presence of other unstated features, elements, components, groups,integers and/or steps. The foregoing also applies to words havingsimilar meanings such as the terms, “including”, “having” and theirderivatives. Also, the terms “part,” “section,” “portion,” “member” or“element” when used in the singular can have the dual meaning of asingle part or a plurality of parts. Also as used herein to describe theabove embodiment(s), the following directional terms “forward”,“rearward”, “above”, “downward”, “vertical”, “horizontal”, “below” and“transverse” as well as any other similar directional terms refer tothose directions of the lens barrel and the imaging device equipped withthe lens barrel. Accordingly, these terms, as utilized to describe thetechnology disclosed herein should be interpreted relative to the lensbarrel and the imaging device equipped with the lens barrel.

The term “configured” as used herein to describe a component, section,or part of a device includes hardware and/or software that isconstructed and/or programmed to carry out the desired function.

The terms of degree such as “substantially”, “about” and “approximately”as used herein mean a reasonable amount of deviation of the modifiedterm such that the end result is not significantly changed.

While only selected embodiments have been chosen to illustrate thepresent invention, it will be apparent to those skilled in the art fromthis disclosure that various changes and modifications can be madeherein without departing from the scope of the invention as defined inthe appended claims. For example, the size, shape, location ororientation of the various components can be changed as needed and/ordesired. Components that are shown directly connected or contacting eachother can have intermediate structures disposed between them. Thefunctions of one element can be performed by two, and vice versa. Thestructures and functions of one embodiment can be adopted in anotherembodiment. It is not necessary for all advantages to be present in aparticular embodiment at the same time. Every feature which is uniquefrom the prior art, alone or in combination with other features, alsoshould be considered a separate description of further inventions by theapplicants, including the structural and/or functional concepts embodiedby such feature(s). Thus, the foregoing descriptions of the embodimentsaccording to the present invention are provided for illustration only,and not for the purpose of limiting the invention as defined by theappended claims and their equivalents.

1. A lens barrel, comprising: a first frame; a second frame rotatablysupported by the first frame; a moving frame guided in the optical axisdirection by the second frame; and a drive actuator that is mounted onthe first frame and rotationally drives the second frame with respect tothe first frame, wherein the second frame has a substantiallycylindrical main body component and a gear component that is disposed onthe inner peripheral face of the main body component and to which thedrive force of the drive actuator is transmitted, and the gear componentis disposed substantially in the middle of the main body component inthe optical axis direction.
 2. The lens barrel according to claim 1,wherein the gear component protrudes inward from the inner peripheralface of the main body component.
 3. The lens barrel according to claim1, wherein the first frame has a substantially cylindrical outer framethat rotatably supports the second frame, and a base member that isfixed to the end of the outer frame, and a holding space is left betweenthe gear component and the base member in the optical axis direction. 4.The lens barrel according to claim 3, wherein the drive actuator has afirst actuator that is fixed to the first frame and generates driveforce, and a transmission mechanism that transmits the drive force ofthe first actuator to the gear component, the first actuator and thetransmission mechanism are disposed on the inner peripheral side of thesecond frame, and the first actuator and/or the transmission mechanismgoes inside the holding space.
 5. The lens barrel according to claim 4,wherein the first actuator has a driveshaft that outputs drive force,and the rotational axis of the driveshaft faces in a different directionfrom the optical axis direction.
 6. (canceled)
 7. The lens barrelaccording to claim 3, wherein part of the moving frame goes into theholding space in a state in which the moving frame is closest to thefirst frame in the optical axis direction.
 8. The lens barrel accordingto claim 7, wherein the second frame has a first cam groove formed inthe inner peripheral face of the main body component, a second camgroove formed in the inner peripheral face of the main body component,and a third cam groove formed in the inner peripheral face of the mainbody component, the moving frame has a first cam follower guided by thefirst cam groove, a second cam follower guided by the second cam groove,and a third cam follower guided by the third cam groove, and at leastpart of the first cam groove is disposed between the gear component andthe base member.
 9. (canceled)
 10. The lens barrel according to claim 9,wherein the inside radius of the bottom face of the first to third camgrooves is greater than the root radius of the gear component. 11.(canceled)
 12. (canceled)
 13. (canceled)
 14. The lens barrel accordingto claim 1, further comprising an electrical contact that is fixed tothe first frame and is electrically connectable to an external device;and an electrical board that is fixed to the first frame and iselectrically connected to the electrical contact, wherein the electricalboard is disposed on the inner peripheral side of the second frame whenviewed in the optical axis direction.
 15. (canceled)
 16. The lens barrelaccording to claim 1, further comprising a first lens frame that issupported movably in the optical axis direction by the first frame andwhose rotation is restricted by the first frame; and a first lens groupthat is fixed to the first lens frame, wherein the first lens frame isdriven in the optical axis direction by the second frame when the secondframe rotates with respect to the first frame.
 17. (canceled) 18.(canceled)
 19. The lens barrel according to claim 1, wherein the rootradius of the gear component is smaller than the inside radius of themain body component.
 20. The lens barrel according to claim 1, whereinthe second frame is guided in the optical axis direction by the firstframe.
 21. The lens barrel according to claim 3, wherein the outer framehas a plurality of guide cam grooves, the second frame has a pluralityof guide cam followers respectively inserted into the plurality of guidecam grooves, and the fixed parts of the base member and the outer frameare disposed between the guide cam grooves in the peripheral direction.22. The lens barrel according to claim 21, further comprising amanipulation member that is disposed on the outer peripheral part of theouter frame and is provided rotatably in the peripheral direction withrespect to the first frame, wherein the manipulation member is disposedat a location that does not overlap the plurality of guide cam grooves.23. (canceled)
 24. (canceled)
 25. The lens barrel according to claim 22,further comprising a restricting member that is disposed on the oppositeside of the outer frame from the base member and is mounted to the endof the outer frame, wherein the manipulation member is rotatablysupported and its movement in the optical axis direction is restrictedby the outer frame and/or the restricting member.
 26. The lens barrelaccording to claim 4, wherein the manipulation member is disposed moreto the subject side than the first actuator in the optical axisdirection.
 27. (canceled)
 28. The lens barrel according to claim 1,wherein at least one of the first lens frame and the moving frame, whennot in use, moves more to the image plane side than its movement regionin the optical axis direction when in use, with respect to the firstframe.
 29. (canceled)
 30. The lens barrel according to claim 14, whereinthe second frame is allowed to overlap the electrical board when viewedin the direction perpendicular to the optical axis direction.
 31. Thelens barrel according to claim 16, wherein the second frame has aplurality of inner peripheral cam grooves formed in its inner peripheralface, the root radius of the gear component is smaller than the insideradii of the bottom faces of the plurality of inner peripheral camgrooves.
 32. The lens barrel according to claim 22, wherein themanipulation member has a portion which is closer to the optical axisthan the bottom faces of the plurality of guide cam grooves.